Chemotherapy and more particularly, combined chemotherapy on the basis of the combination of agents with different action mechanisms, is today an established therapeutic principle for combating cancer. Thus the combination of different anti-tumour agents can be a way of increasing anti-tumour effectiveness when a synergic effect is shown and/or when a reduction in toxicity is observed.
In the present Application, the expression “pyrrolobenzodiazepine derivative” comprises the product of formula (I)

in which the dotted lines represent a second optional bond between the atoms to which they are attached, and                when a second bond is present between the carbon to which X is attached and the nitrogen atom to which R is attached, then R is absent and X represents hydrogen, or        when there is no second bond between the carbon to which X is attached and the nitrogen atom to which R is attached, then R represents hydrogen and X represents—OH,        
and                when a second bond is present between the carbon to which X1 is attached and the nitrogen atom to which R1 is attached, then R1 is absent and X1 represents hydrogen, or        when there is no second bond between the carbon to which X1 is attached and the nitrogen atom to which R1 is attached, then R1 represents hydrogen and X1 represents—OH,        
or an addition salt with an acid and/or a solvated form and/or a hydrated form of such a compound, in amorphous or crystalline form, in racemic form or in an optically active form or all combinations of these forms,
and/or any compound which can generate, under physiological conditions, one of the compounds as defined above,
and/or any mixture of some of the compounds or all the compounds listed above.
Another definition of the “pyrrolobenzodiazepine derivative” is as follows: the product of formula (II)

and/or a mono- and/or bis-carbinol formed by adding water or alcohol,
and/or an addition salt with an acid and/or a solvated form and/or a hydrated form,
and/or an addition salt with an acid and/or a solvated form and/or a hydrated form of such a compound, in amorphous or crystalline form, in racemic form or in an optically active form,
and/or any compound which can generate, under physiological conditions, one of the compounds as defined above,
and/or any mixture of some of the compounds or of all the compounds listed above.
Subsequently, the pyrrolobenzodiazepine derivative as defined above, will be referred to as a “PBD derivative”. Such a PBD derivative of this type can be prepared according to the method described in WO 00/12508.
Fludarabine (commercially available in France under the trade name Fludara®) is a product for which the principal therapeutic indications are chronic lymphoid cancers such as chronic lymphoid leukaemia and malignant lymphomas.